Stamp-mill



UN TED STATES PATENT OFFICE.

WILLIAME. PARNALnoF CALUMET, AND CHARLES H. KRAUSE, or some LAKE LINDEN, MICHIGAN.

STAMP-MILL.

SPECIFICATION forming part of Letters Patent No. 689,219, dated December 17, 1901.

v Application filed September 3, 1898. Serial No. 690,154. (No model.)

To all whom it may concern:

Be it known that we, WILLIAM E. PARNALL, residing at Galnmet,and CHARLES H.KRAUSE, residing at South Lake Linden, in the county of Houghton and'State of Michigan, citizens of the'United States, have invented certain new and useful Improvements in Stamp-Mills, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

Our i nvention relates particularly to stain pmills for' crushing copper ore such as is obtained in the Lake Superior region, in which.

flakes or pieces of pure metal varying in size are found embedded in or adhering to very hard rock.

Its main objects are to increase the capacity and generally to improve the construction and operation of machines of this class.

It consists in certain novel features of construction and arrangements of parts, as hereinafter particularly described, and pointed out in the'claims.

In the accompanying drawings like letters designate the same parts in both figures. v

Figure 1 is a vertical medial section on the line 2 2, Fig. 2, of astamp-mill embodying our invention; and Fig. 2 is a horizontal section of the same on the line 1 1, Fig. 1.

For crushing ore of the kind above mentioned powerful steam-actuated stamp-mills are generally employed. These mills are usually provided with single stamps and housings or casings inclosing the space around the stamps and above the mortars and constituting permanent framework for carrying the roof over the mortars and for holding the screens. The housing or casing has from one to four openingsordinarily two or four, ar-

ranged on opposite sides of the stamp and mortar-and these openings are provided with straight flat or plane screens, which are usually inclined outward toward the top and are located at some distance from the stamp and the cavity in the mortar. It will be apparent that only a small part of such plane screens can be perpendicular to the splash,

whichradiates from all sides of the stamp, and that pieces of free metal small enough to pass straight through holes in that part of a screen which is perpendicular to the splash cannot pass obliquely through holes of the same size in other parts of the screen, but. will be thrown back into the mortar and subjected again to the powerful blows of the stamp. This repeated action of the stamp upon free pieces of copper is undesirable for several reasons: It reduces the capacity of the mill and correspondingly increases the cost of crushing a given quantity of ore, it 6::

- increases the losses in fine material and slimes which are produced by the repeated pounding of the free metal, and it impairs the quality and value of the copper, particularly for electrical purposes, because the longer the copper is retained in the mortar the greater will be the percentage of iron mixed with it from the constant wear and abrasion of the stamp, stave-liners, and parts of the mill which are exposed to the cutting and abrading action of the hard crushed rock, sand, or pulp. The permanent frame work forming a considerable part of the inclosure around the stamp and mortar reduces to that extent the screening area, and consequently the discharging capacity, of such mills and m ust be protected by linings which are exposed to the powerful splash of sharp pulp or sand from the heavy stamp, and consequently are subjected to rapid abrasion and wear and must be frequently renewed, thus entailing constant care, trouble, and expense. For crushing ore of the character hereinbefore mentioned mills having mcrethan one stamp working in the same inclosnre are impracticable on account of the strong splashpf hard sharp pulp or rock, which would rapidly cut away the stamp-shoes and lower parts of the stamps. Furthermore, the splash of each stamp intercepts that of the other stamp or stamps in the same inclosure and prevents to a considable degree the discharge through the screens of the crushed orecarried by the splash. It follows,therefore, that in the powerful stampmills above referred to having plane screens arranged in the openings of a permanent casing or framework which forms a considerable part of the inclosure around the mortar, particularly in mills having more than one stamp in the same inclosure, their capacity to crush too the ore and free the metal is much greater than their capacity to discharge or get rid of their effective area for the discharge of the pulp or sand and free metal is increased to a "maxim um, while the area of permanent parts of the mill exposed to the abradingand destructive effect of the splash is reduced to a minimum, the capacity of the mill is greatly increased loss in fine material and slimes is reduced, the quality of the metal obtained is improved, and the time, trouble, and expense required to renew linings and parts exposed to abrasion are to a great extent avoided. By makingthe screen and splashpan in separately-removable sections a great saving is effected, sincethose parts that are subjected to more rapid wear may be renewed from time to time as they become worn out and unfit for use Without discarding or disturbing other parts whichinay still be serviceable. The mortar and stamp being completely surrounded by the screen and splashpan,which can be easily removed in sections, either partially or wholly, are more easily accessible for inspection and repair than when they are partially inclosed on the sides by a permanent casing or housing.

Referring to the drawings, illustrating a stampmill embodying our invention in its preferred form as to the construction and arrangement of the essential parts of the ma chine, A designates the mortar, which is formed in the upper side ith a central cavity for holding the ore to.be pulverized or crushed, and with a channel a around said cavity for catching and conducting off the pulp or sand. It is also formed outside of said channel with flanges or projections a a for the support and attachment of columns B B, which carry at their upper ends the roof 0. These columns are cored out to receive the rods or bolts D, which pass through them, the flanges or projections a on the mortar, and the roof 0 and are provided at their ends with nuts for firmly binding and holding the several parts together.

E is the stamp, which has a vertical reciprocating movement and a slow rotary movement imparted thereto by the usual or any suitable means, which it is not deemed necessary to illustrate or particularly describe, as they do not constitute a part of the invention claimed and are not essential to a clear understanding thereof. .The stamp is provided in the usual way with a detachable chilled or hardened iron shoe 6. The central cavity in the mortar is provided on the sides with the usual stave-liners F and at the bottom with a die G, which is held in place by a ring H. The roof 0 is formed with an opening 0, through which the stamp-shaft projects and through which the ore to be crushed stave-liners, die, and ring are, like the stampshoe, usually made of chilled iron and are readily removable, so that they can be easily replaced when worn out. The channel a, the under side of the roof, and those parts of the machine which are exposed to the splash and with which the pulp or sand comes in contact are protectedby linings of chilled iron, boiler-plate, or other suitable material which can be easily removed and renewed from time to time.

The mortar A is supported by an anvil I and is held in place thereon by a raised portion'of the top of the anvil fitting a recess in .is fed, with water, into the mortar. These the bottom of the mortar, as shown in Fig.

mortar within the channel a. The screen-sections are preferably made of perforated metal plates, which are clamped between and strengthened at their edges by frames j 3'. These framesbear at the top and bottom against and are supported on the inside by shoulders-formed or provided for the purpose on the upper side of the mortar and on the under side of the roof. The screen is preferably madeof approximately cylindrical form and its sections arranged concentrically with the vertical axis of the stamp and mortar; but any form of arrangement whereby the several parts of the screen will be disposed approximately perpendicular or transverse to the direction of the splash from the stamp and mortar are within the spirit and intended scope of the invention. A splashpan composed of sections K K of sheet or plate metal corresponding in number, form, and arrangement with the sections of the screen surrounds the screen and serves to intercept the pulp or sand discharged through the screen and to deflect the same downward into the channel CL, from which it is conducted through one or more spouts a a (shown in Fig. 2) intolaunders. The splashpan sections are bent inward at the sides which are adapted to rest against the sides of the screen-frames, and they are cut away or left open at the bottom, as shown in Fig. 1, to allow the pulp or sand to flow underneath them into the channeld. Each splashpan section K and the adjacent screen-sec tion J are held in place by screw rods or bolts L, which are threaded in the columns B, extend radially inward therefrom, and hear at their inner ends against the inturned sides of the splash-pan sections. Theserods or bolts L are provided with jam-nuts Z, by which they are locked in place when they are set up against the splash-pan sections K. With this construction and arrangement of the screen and splash-pan and the means shown and described for holding the sections in place any section can be readily removed and replaced without disturbing the others, and the columns and main parts of the framework of the machine are protected by the splash-pan against contact with the pulp or sand, which rapidlywears away parts of the machine exposed to it. The capacity of the machine is also materially increased. The maximum amount of ore that it has been possible to crush with a stamp-mill of this class as here: tofore constructed is about four hundred tons in twenty-four hours; but with a machine substantially like that herein shown and described nearly or quite six hundred tons'ca be crushed in the same tiln e. We do not wish to be understood as limit ing ourselves to the exact details of construction as shown and described except as to those claims in which such details are expressly in cluded.

We claim l 1. In a stamp-mill the combination with a single stamp provided with a detachable hardened shoe and a mortar having a cavity provided with a removable hardened die and hardened stave-liners constructed and arranged to receive the impact of the pulp and to direct the same upwardly and outwardly on all sides, of a removable cylindrical screen surrounding the stamp concentrically therewith so as' to be approximately perpendicular to the direction of the splash passing through it on all sides of the mortar, and a removable splash-pan surrounding said screen and open at the bottom so as to intercept the pulp passingsthrongh said screenand to afford a free and constant discharge therefor,

v substantially as and for the purposes set forth.

2. In a stamp-mill the combination with a single stamp provided with a detachable hardened shoe and a mortar formed with a central cavity and with a channel surrounding said cavity which isprovided with a removable die and stave-liners constructed and arranged to receive the impact of the pulp and to direct the same upwardly and outwardly on all sides, of a removable cylindrical screen arranged concentrically with said stamp between the cavity and channel in the mortar, and a removable imperforate splash-pan inclosing a space outside of said screen and open at the bottom so as to afford a free discharge for the pulp into the channel in the mortar, substantially as and for the purposes set forth.

3. In a stamp-mill the combination with a single stamp provided with a detachable hardened shoe and a mortar having a cavity provided with a removable hardened die and stave-liners constructed and arranged to receive the impact of thepulpand to direct the same upwardly and outwardly on all sides, of

a cylindrical screen surrounding the stamp concentrically and composed of separately-removable sections, and a splash-pan su rrounding said screen and composed ofcorresponding separately-removable sections opening at the bottom into a suitable discharge-conduit, substantially as and for the purposes setforth. 4. A stamp-mill comprising the framework, a stamp, a mortar audits cavity, a screen composed of sections surrounding the stamp and the cavity of the mortar, and a splashpan composed of corresponding sections surrounding the screen, both the screen and the splash pan being interposed between the stamp and the framework and protecting the framework against the splash from the stamp, substantially as described.

5. A stamp-mill comprising a stamp, a mortar having a cavity and a channel surrounding the cavity, columns arranged outside of said channel, a roof supported above the mortar upon said columns, bolts passing through said columns and roof and provided with nuts firmly binding and securing the parts together, a screen surrounding the cavity in the mortar inside of said channel, and a removable splash -pan interposed between said screen and said columns, substantially as and i for the purposes set forth.

6. A stamp-,mill comprising a stamp, a mortar and its cavity, columns rising from the outer portion of the mortar, a roof supported on the columns,said mortar and roof being provided witlfcorresponding shoulders, a screen composed of sections surrounding the cavity in the mortar inside of said columns and bearing on the inside at, the top and bottom against the shoulders of the roof and mortar, and radially-disposed screw rods or bolts threaded in said columns and holding said screen-sections from the outside against said shoulders, substantially as and for the purposes set forth.

7. A stamp-mill comprising a stamp, a mortar having a cavity and a channel around the cavity, columns rising from the mortar outside of said channel, a roof supported on said columns, said roof and mortar having corresponding shoulders or abutments, a screen composed of sections surrounding the cavity in the mortar, a splash-pan composed of corresponding sections having inwardly-turned sides adapted to rest against the sides of the screensections,and screw rods or bolts threaded in said columns transversely thereto and adapted to bear at their inner ends against the inturned sides of the splash-pan sections and to hold them with the screen-sections against the shoulders or abutments on the mortar and roof, substantially as and for the purposes described.

In witness whereof we hereto affix our signatures in presence of two witnesses.

' WILLIAM EVPARNALL.

CHARLES H. KRAUSE. Witnesses:

A. R. PARNALL, W. M. HARRIS. 

